Machine for mixing concrete mixtures and for washing sand and the solid ingredients thereof



NOV. 25! 1924' J. S. LANCASTER MACHINE FOR MIXING CONCRETE MIXTURES ANDFOR WASHING SAND AND THE SOLID INGREDIENTS THEREOF Filed Nov. 28 1923 3Sheets-Sheet l New. 25, 1924. v 1,516,773

5. LANCASTER Y J. MACHINE FOR MIXING CONCRETE MIXTURES AND FOR WASHINGSAND AND THE SOLID INGREDIENTS THEREOF Filed Nov 28, 1923 3 Sheets-Sheet2 ,P." -Q T: 5

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Nov. 25, 1924- 1,516,773

J. S. LANCASTER MACHINE FOR MIXING CONCRETE MIXTURES AND FOR WASHINGSAND AND THE SOLID INGR DIENTS THEREOF Filed Nov. 28, 1923 5Sheets-Sheet 5 atented Nov. 25, 1924.

STATES PATENT OFFICE.

JOHN STUART LANCASTER, OF WARWICK, ENGLAND, ASSIGNOR O'E ONE-HALF TOJOHN FAULDER BURN, OF LONDON, ENGLAND.

MACHINE FOR MIXING CONCRETE MIXTURES AND FOR WASHING SAND AND THE SOLIDINGREDIENTS THEREOF.

Application filled November 28, 1923. Serial No. 677,487.

" of the King of .Great Britain and Ireland,

have invented a new and Improved Ma chine for Mixing Concrete Mixturesand for Washing Sand and the Solid Ingredients Thereof (for which I havefiled application in Great Britain No. 32,7 53filed the 30th November,1922, and accepted Feb. 29, 1924, and numbered 211,965), of which thefollowing is a specification.

This invention relates to a machine for mixing concrete, the samestructure being adapted to be used for mixing ingredients of othersubstances. The invention has advantages, inasmuch as it provides amachine which may deliver a continuous discharge of the mixture ifsuitably fed, and the point of discharge may conveniently be arranged tobe higher than the feeding hopper, so that the machine partakes of thenature of an elevator as well as fulfilling its primary function.

According to the invention, a mixing cylinder or drum is provided,rotating on its axis, which is inclined to the horizontal, and means areprovided for feeding in the ingredients or substance to be dealt withinto the lower end, for continuously agitating it and simultaneouslyeffecting an axial dis placement until it approaches the upper end fromwhence it is discharged, through a chute, such means comprising anarrangement of inclined segmental bafile plates and beyond the higherbaflle plates lifters for carrying and discharging the mixture into achute which is maintained so that one end will enter the higher end ofthe drum, as will be described.

The invention, as applied to a machine for mixing concrete, comprises arotatable cylindrical drum, which is maintained at a suitable angle, say25, to the horizontal and means are provided for rotating the drum onits axis. The upper end of the drum is open, and the lower end partiallyclosed by an annular conical end-plate, c ntral space of which, thematerial is fed b a hopper or chute, Water may be fed through the alsointo the lower end or any other con venient part of the cylinder. Insidethe drum are provided pockets which are formed by fixed segmentalpartitions or plates, and in effect, presenting a substantially helicalseries of pockets through which the material passes, being carried bythe plates and falling from a lower pocket into another higher up. theseries. The individual pockets are arranged so that, with respect to thedirection of rotation of the drum, their leading ends are axially lowerthan their rear ends, so that the material is axially translated orcarried whilst in the pocket. Further, the leading end of one pocket isarranged to come partially beneath the rear end of the previouslyoccupied pocket, in the rotation of the drum. Thus the material beingfed into the lower or first pocket in the series, is carried aroundtherein until, falling back by its own weight, it leaves the pockethigher up the drum axially, than it entered. It leaves one pocket,moreover, mostly to fall into the next, which carries it still furtherup the drum, a very effective agitation and mixture-promoting movementbeing continuously maintained.

The machine as applied to a washing machine is provided with a watersupply at or near the upper end of the drum. The segmental plates are inthis case perforated, the size of the perforations depending on thenature or grading of the material which is intended to be washed fromthe bulk. Suitable draining holes are provided at the lower end of thedrum for emitting the washings. In certain cases it may be founddesirable to retain the material in the pocket until it has been carriedwell up by the rotation of the drum. This may be provided for byretaining pieces over the rear ends of the pockets so constructed as toretain the material in the pocket considerably after the point where itwould normally fall into the next pocket of the series.

The drum of the present mixer is rotated preferably at a slow speed,giving the advantage over existing types that the material has time toslide down the walls of the pockets, further it is very thoroughly andintimately mixed, v

The drawings illustrate the invention as appliedto a transportable mixerfor concrete or the like, adapted to be driven from any convenient powersource. The features of the invention are shown in Fig. 1 which is anelevation of the drum on its carriage, part being broken away and hiddenparts being shown in broken lines.

Fig. 2 is an end elevation of the drum, sectional on line 2 of Fig. 1,the drum being rotated through 90.

Fig. 3 is a sectional elevation showing the interior arrangement, theview being that of Fig. 1, the drum being rotated through 90.

Fig. 4 is a partly sectional view of the drum showing one half swungback as for cleaning etc.

The mixing drum comprises two semi-cylindrical casing portions 1 and 2,hinged together along adjacent edges by hinges 3 and fitted withsuitable simple fasteners 4; to hold their other edges together in use.

The half 1 of the caslng is permanently attached to end pieces 5 and 6.End member 5 has formed integrally with it or suitably attached to it, alarge bevel pinion 5 a roller track 5 and a frustro-conical annularflange 5 through the central aperture 5 of which, material is fed intothe drum. The member 6 has also a roller track 6 an annular flange 6,and an aperture 6. The mouth or exterior of the flange 6 is flared, asis seen from Figs. 3 and 1 at G to aid discharging. The rear face of thebevel 5 conveniently forms a race for small rollers 7 which take theaxial thrust of the inclined drum (see Figs. 1 and 3) and rollers 8cooperate with tracks 5 and 6 to take the weight of the drum. The drumis thus a rotatable cylinder, constructed so as to permit of its beingopened for inspection etc.

The opening 5 is entered by the lower chute portion of a hopper 9 forfeeding material into the drum, and a discharge chute 10 is pivotallymounted at 10 and provided with an operating and balance lever 11 sothat it may be swung outwardly to the horizontal when not required todischarge, in the position shown in Fig. 3. The hopper 9 is preferablyprovided with. a sliding gate 9 operated by a lever 9 in order that theflow of material into the drum may be regulated.

The rollers 7 and 8, supporting the drum, are carried in rings 7suitably attached as by bolted brackets 7 to the framework 12 of themachine. The ring 7 at the upper end of the drum may be complete or onlysemicircular, as shown, as desired.

The framework 12 is conveniently made upof stout H or U section members,and conveniently is borne on cast iron running rollers or wheels 12 fortransport of the machine from one location to another. The

frame 12 also carries in a journal bracket 12 a driving bevel pinion13., co-operating with the bevel 5 to rotate the drum. A motor may becarried on the frame 12 or an auxiliary plant may be used for driving.

The principal constructional feature of the invention relates to theinternal arrange ment of the drum. As stated, the drum consistsprimarily of two halves l and 2. Each half has mounted in it, secured bysuitable angle pieces 14 baflie plates 15 in the form of semicircularplates of metal, and disposed with their straight edges diametrically tothe drum and at an angle to its axis. The corresponding plates 15 inopposite halves 1 and 2 of the drum are arranged so that their straightedges cross, and, where they cross, practically if not actually meet, atpoints 15 which is only approximately indicated in Figs. 2 and 3. Theplates 15in each half, are arranged in parallel planes and thus formdeep segmental pockets 16 in which is to be found the mix. Owing to thedisposition of the plates which on one side are preferably at a greaterinclination to the axis than on the other, the pockets 16 on oppositesides of the drum overlap so that, in the course of rotation of thedrum, a part of the material in one pocket falls or slips down into thenext pocket on the opposite side of the drum. The inclination of theplates 15 is in effect helical, so that the material in the pocket 16is, during the rotation, carried up the slope of the drum as it falls orslips back in the pocket. Above the series of pockets 16 in the drum arearranged deflecting blades 17, disposed so as to pick up material andcarry it up to a certain height, and then to shoot their contents in anaxial direction on to the discharge chute 10 if the latter is in itsoperative position or alternatively simply to drop the material backinto the lower part of the drum. The chute 10, when in operativeposition, interrupts the fall and directs the material out throughaperture 6 thus discharging the drum. The hopper 9 of course feeds thelower end of the drum so that the first plate 15 catches the material.

The tumbling and agitation of the mix renders it effective in promotingthorough and even mixing. Water is fed into the drum by a pipeconveniently arranged to project through the aperture 5 in mixingordinary concrete. It will be observed that operation may be renderedcontinuous even though the feed or discharge may be interrupted forlimited periods without practically affecting the desired delivery. Itis advisable to open the drum and flush it with water before leaving themachine out of action.

It will be realized that the drawings illus trate and the abovedescription refers to one type of concrete mixer only. As previouslytions, semi-circular plates carried by the sections and so assembledthat the chords of the semi-circular plates will cross each other, andmeans for feeding material into the lower end of the drum anddischarging the same from the higher upper end of the drum.

2. In a machine for mixing concrete, a drum having semi-cylindricalcentral portions, semi-circular blades attachedto the interior of thesections of the drum and positioned so that the chords ofthesemi-circular blades will cross each other at an angle, liftingscoops carried by the interior of the drum and located adjacent to thedischarge end thereof, a discharge chute adjustably connected to thesupporting frame of the drum, and means for changing the position of thechute. s.

3. In a concrete mixing machine, a drum mounted at an inclination andprovided with means for rotating the same, one head of said drum havingan inclined flange with an aperture therethrough, a chute leading intoand discharging material at the lower portion of the drum, the oppositeend of the drum having inclined portions surrounding the dischargeopening, blades located adjacent to the upper end of the interior of thedrum, semi-circular plates attached to the interior of the drum andmaintained therein so that the chords of said plates will be inintersecting relation one to the other,

and means for rotating the drum maintained at an inclination to thehorizontal.

4. In a mixing machine, a cylinder mounted for rotation on an inclinedaxis, the central portion of said cylinder being made up of twosemi-cylindrical portions each having at the inner sides thereofsemi-circular plates, the straight margin of the said semicircularplates being attached to respective sections of the drum so that theywill cross each other in line with the junction of the two sections ofthe drum, means for feeding material to be mixed into the lower end ofthe cylinder, means for maintainin and rotating the cylinder while in anincilined position, heads attached to the semi-cylindrical sections ofthe cylinder, each of the heads having apertures therethrough, the partsbeing organized whereby the material fed into the cylinder isprogressively carried upward and toward the higher opposite dischargeend.

5. In a mixing machine, a cylinder, a central portion thereof comprisingtwo connected semi-cylindrical portions which are hingedly connected oneto the other, a plurality of semi-circular plates attached to eachsection of the cylinder, the plates of each section being parallel andspaced so that the chords thereof will cross the chords of the plates onthe opposite section, curved blades adjacent to one end of the cylinder,and a discharge chute maintained to extend into the higher (portion ofthe cylinder so that said inwar ly extending end will be below theblades when in their raised position.

In witness whereof I have signed this specification.

JOHN STUART LANCASTER.

